s1_generate_a_series_of_files(){
for (( index=1; index<=100; index++)); do
	file="/tmp/new_file${index}"
	echo -n "${index}" > "${file}"
done
}
s2_list_4_files_in_long_format_about_account_and_group(){
Is -1 /etc/passwd /etc/shadow /etc/group /etc/gshadow | sort
}
s3_find_items_related_to_given_username(){
username="$1"
grep "^${username}:" /etc/passwd /etc/shadow | sort
}
s4_find_items_realated_to_given_group_name(){
groupname="$1"
grep "^${groupname}:" /etc/group /etc/gshadow | sort
}
s5_create_groups_for_given_group_names(){
groupadd rnd
groupadd itoperation
}
s6_create_users_and_set_their_group_as_required(){
useradd -G rnd Adam
useradd -G rnd Bob
useradd -G itoperation Calvin
useradd -G itoperation David
useradd -G rnd Edward
}
s7_change_users_shell(){
usermod -s /usr/bin/sh Adam
usermod -s /usr/bin/sh Edward
}
s8_set_password_change_policy(){
for user in Adam Bob Calvin David Edward; do
	chage -m 10 -M 60 "$user"
done
}
s9_set_password_for_five_users(){
	usernames=("Adam" "Bob" "Calvin" "Edward")
	for ((i=0; i<${#username[@]}; i++)); do
		echo "${usernames[$i]}:${@:$i+1:1}" | chpasswd
	done
}
s10_lock_bobs_password(){
passwd -1 Bob
}
s11_include_adam_into_wheel_group(){
usermod -aG wheel Adam
}
s12_change_files_permission(){
	for ((i=3; i<=99; i+=3)); do
		file="/tmp/new_file${i}"
		chmod 640 "$file"
	done
}








